Ethanol infiltration into the stapedio-vestibular joint reduces low-frequency vibration of the ossicular chain and round window membrane in the guinea pig

BACKGROUND

The synovial stapedio-vestibular joint (SVJ), which serves as a bridge between the stape and oval window, can be found in guinea pigs and most human adults. Unlike the fibrous SVJs in other animals, the contribution of the synovial SVJ to middle ear sound transmission remains unknown.

AIMS/OBJECTIVES

In this study, we investigate whether sclerosis of the synovial SVJ contributes to frequency-dependent vibration of the ossicular chain and round window membrane (RWM).

MATERIALS AND METHODS

A model of SVJ sclerosis model was established in the guinea pig using 75% ethanol. A laser Doppler vibrometer was then used to measure vibrations of the RWM and the long process of the incus (LPI) under pure tone sound stimulations of 0.25-16 kHz. The influence of SVJ sclerosis was analysed by comparing structural vibration displacement between the normal and sclerosis groups.

RESULTS

Both LPI and RWM vibrations significantly decreased at low frequencies after infiltration of ethanol, which caused SVJ sclerosis.

CONCLUSIONS

SVJ sclerosis reduces low-frequency vibration of the ossicular chain and RWM in the guinea pig, which indicates that the synovial SVJ is vital to low-frequency sound transmission in the middle ear.

SIGNIFICANCE

Providing useful data for further research regarding middle ear biomechanics.

Linking a cell-division gene and a suicide gene to define and improve cell therapy safety

Human pluripotent cell lines hold enormous promise for the development of cell-based therapies. Safety, however, is a crucial prerequisite condition for clinical applications. Numerous groups have attempted to eliminate potentially harmful cells through the use of suicide genes¹, but none has quantitatively defined the safety level of transplant therapies. Here, using genome-engineering strategies, we demonstrate the protection of a suicide system from inactivation in dividing cells. We created a transcriptional link between the suicide gene herpes simplex virus thymidine kinase (HSV-TK) and a cell-division gene (CDK1); this combination is designated the safe-cell system. Furthermore, we used a mathematical model to quantify the safety level of the cell therapy as a function of the number of cells that is needed for the therapy and the type of genome editing that is performed. Even with the highly conservative estimates described here, we anticipate that our solution will rapidly accelerate the entry of cell-based medicine into the clinic.

Continued Emissions of the Ozone-Depleting Substance Carbon Tetrachloride From Eastern Asia

Carbon tetrachloride (CCl₄) is an ozone-depleting substance, accounting for about 10% of the chlorine in the troposphere. Under the terms of the Montreal Protocol, its production for dispersive uses was banned from 2010. In this work we show that, despite the controls on production being introduced, CCl₄ emissions from the eastern part of China did not decline between 2009 and 2016. This finding is in contrast to a recent bottom-up estimate, which predicted a significant decrease in emissions after the introduction of production controls. We find eastern Asian emissions of CCl₄ to be 16 (9-24) Gg/year on average between 2009 and 2016, with the primary source regions being in eastern China. The spatial distribution of emissions that we derive suggests that the source distribution of CCl₄ in China changed during the 8-year study period, indicating a new source or sources of emissions from China's Shandong province after 2012.

Identification of long non-coding RNAs in the chalkbrood disease pathogen Ascospheara apis

Ascospheara apis is a widespread fungal pathogen that exclusively invades honeybee larvae. Thus far, non-coding RNA in A. apis has not yet been documented. In this study, we sequenced A. apis using strand specific cDNA library construction and Illumina RNA sequencing methods, and identified 379 lncRNAs, including antisense lncRNAs, lincRNAs, intronic lncRNAs and sense lncRNAs. Additionally, these lncRNAs were found to be shorter in length and have fewer exons and transcript isoforms than protein-coding genes, similar to those identified in mammals and plants. Furthermore, the existence of 15 predicted lncRNAs of A. apis was confirmed using RT-PCR and expression levels of 11 were lower than those of adjacent protein-coding genes. Our findings not only enlarge the lncRNA database for fungi, but also lay a foundation for further investigation of potential lncRNA-mediated regulation of genes in A. apis.

Transurethral fluorescence cystoscopy guidance for total resection of bladder tumor

The purpose of this work is to investigate the total resection of bladder tumor under transurethral fluorescence cystoscopy. Nineteen patients with bladder tumor, from which we resected a total of 26 tumors, including 16 single tumors with diameters of 0.5~2 cm, were enrolled in the study. All tumors were located in the posterior wall or neck of the bladder. For the surgery, the size and location of tumors in the bladder were observed by fluorescence cystoscopy. Then, plasma electrocision was used to cut the full-thickness of the bladder to the fat outside of the bladder along the near-end of the tumor, then along the left and right side of bladder (to the far-end), and the full-thickness of the tumor was resected. Finally, the far-end tumor was removed and the full-thickness of the bladder at the bottom was completely resected. All operations were completed successfully within 10-40 min. There was little bleeding during surgery and no secondary bleeding after surgery. Tumor staging found 17 patients at T1 stage (20 tumors) and 2 patients at T2 stage (6 tumors). Patients were followed up for 6~12 months without any recurrence. We show here that total resection of bladder tumor can be accomplished under transurethral fluorescence cystoscopy and preventative resection can be conducted on the suspicious bladder wall with precision to eliminate tumor residue that promotes recurrence.

Comparative Transcriptome Analysis Identifies Putative Genes Involved in Steroid Biosynthesis in Euphorbia tirucalli

Phytochemical analysis of different Euphorbia tirucalli tissues revealed a contrasting tissue-specificity for the biosynthesis of euphol and β-sitosterol, which represent the two pharmaceutically active steroids in E. tirucalli. To uncover the molecular mechanism underlying this tissue-specificity for phytochemicals, a comprehensive E. tirucalli transcriptome derived from its root, stem, leaf and latex was constructed, and a total of 91,619 unigenes were generated with 51.08% being successfully annotated against the non-redundant (Nr) protein database. A comparison of the transcriptome from different tissues discovered members of unigenes in the upstream steps of sterol backbone biosynthesis leading to this tissue-specific sterol biosynthesis. Among them, the putative oxidosqualene cyclase (OSC) encoding genes involved in euphol synthesis were notably identified, and their expressions were significantly up-regulated in the latex. In addition, genome-wide differentially expressed genes (DEGs) in the different E. tirucalli tissues were identified. The cluster analysis of those DEGs showed a unique expression pattern in the latex compared with other tissues. The DEGs identified in this study would enrich the insights of sterol biosynthesis and the regulation mechanism of this latex-specificity.

Comparative Study for the Association of Mitochondrial Haplogroup F+ and Metabolic Syndrome between Longevity and Control Population in Guangxi Zhuang Autonomous Region, China

BACKGROUND

Our previous study suggested that mitochondrial haplogroup F (mtDNA F) was a longevity-associated biomarker, but the effect of mitochondrial haplogroup F on longevity individuals with metabolic syndrome (MetS) was not clear. Thus we explored the association between mtDNA F and MetS among longevity and control population in Guangxi Zhuang Autonomous Region, China.

METHOD

A total of 793 individuals consisting of 307 long-lived participants and 486 local healthy controls were involved in this study. Genotypes of mtDNA F were amplified by polymerase chain reaction and Sanger sequenced. MetS was defined according to the revised National Cholesterol Education Program's Adult Treatment Panel III (NCEP ATPIII ) criteria.

RESULTS

The prevalence of MetS in longevity group (28.0%) was higher than that (18.5%) in control group (P=0.002). Through the case-control stratify analysis, the prevalence of MetS in mtDNA F+ longevity individuals (29.8%) was 4.6 fold higher than that (5.3%) in local control group (P<0.001). However, after further longevity-only analysis, no association between MetS and mtDNA F+ in longevity group was observed (P=0.167). Following same analysis of two variables in control group, we found that the prevalence of MetS in mtDNA F- (95.8%) was higher than that in mtDNA F+ (5.3%); conversely, the prevalence of non-metabolic syndrome (NMetS) in mtDNA F+ (94.7%) was markedly higher than that in mtDNA F- (4.2%) (P<0.001).

CONCLUSION

We demonstrated that mtDNA F+ , as a molecuar biomarker, might not only confer beneficial effect to resistance against MetS but also function as a positive factor for long-life span among the population in Guangxi Zhuang Autonomous Region, China.

HMPA-Catalyzed One-Pot Multistep Hydrogenation Method for the Synthesis of 1,2,3-Trisubstituted Indolines

A convenient and facile method was developed for the synthesis of 1,2,3-trisubstituted indolines. Starting from indole derivatives and ketones/aldehydes, the corresponding indoline products could be obtained with high yield by the hexamethylphosphoramide (HMPA) catalyzed indole Friedel–Crafts reaction, reduction and direct reductive amination process.

ZEB1 promotes prostate cancer proliferation and invasion through ERK1/2 signaling pathway

OBJECTIVE

Prostate cancer is a kind of malignancy with high occurrence in the male urogenital system. However, the mechanism of the occurrence, the progression, and the metastasis of prostate cancer are still unclear. Searching for the effective molecule target is of great significance to improve the curative effect on prostate cancer. Zinc finger E box binding protein-1 (ZEB1) protein is a member of the zinc finger transcription factor family that participates in the embryonic development and formation. ZEB1 was found to be involved in the occurrence and in the development of multiple cancers, while its role in prostate cancer still needs elucidation.

MATERIALS AND METHODS

Normal prostate cell line PC-3M and prostate cancer cell line DU145 were cultured in vitro and transfected by ZEB1 siRNA. ZEB1 mRNA and protein expressions were detected by real-time PCR and Western blot assay. Cell proliferation was determined by using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Cell migration was evaluated by transwell assay. Cell apoptosis was evaluated by caspase-3 activity. The impact of ZEB1 on extracellular signal-regulated kinase 1 and 2 (ERK1/2) signaling pathway was assessed by Western blot assay.

RESULTS

ZEB1 expression significantly increased in DU145 cells compared with PC-3M cells (p<0.05). ZEB1 mRNA and protein obviously declined, cell proliferation inhibited, cell invasion suppressed, and Caspase-3 activity enhanced in DU145 cells after ZEB1 siRNA transfection (p<0.05). ZEB1 siRNA markedly decreased ERK1/2 phosphorylation in DU145 cells compared with control (p<0.05).

CONCLUSIONS

Inhibition of ZEB1 promoted prostate cancer apoptosis, restrained proliferation, and suppressed invasion through down-regulating ERK1/2 signaling pathway.

Hepatic cyclooxygenase-2 overexpression induced spontaneous hepatocellular carcinoma formation in mice

Cyclooxygenase (COX)-2 is upregulated in hepatocellular carcinoma (HCC). However, the direct causative effect of COX-2 in spontaneous HCC formation remains unknown. We thus investigate the role and molecular pathogenesis of COX-2 in HCC by using liver-specific COX-2 transgenic (TG) mice. We found spontaneous HCC formation with elevated inflammatory infiltrates and neovessels in male TG mice (3/21, 14.3%), but not in any of male WT mice (0/19). Reduced representation bisulfite sequencing (RRBS) and gene expression microarrays were performed in the HCC tumor and non-HCC liver tissues to investigate the molecular mechanisms of COX-2-driven HCC. By RRBS, DNA promoter hypermethylation was identified in HCC from TG mice. Induction of promoter hypermethylation was associated with reduced tet methylcytosine dioxygenase 1 (TET1) expression by COX-2. TET1 could catalyze the conversion of 5-methylcytosine into 5-hydroxymethylcytosine (5hmC) and prevents DNA hypermethylation. In keeping with this, loss of 5hmC was demonstrated in COX-2-induced HCC. Consistently, COX-2 overexpression in human HCC cell lines could reduce both TET1 expression and 5hmc levels. Integrative analyses of DNA methylation and gene expression profiles further identified significantly downregulated genes including LTBP1, ADCY5 and PRKCZ by promoter methylation in COX-2-induced HCC. Reduced expression of LTBP1, ADCY5 and PRKCZ by promoter hypermethylation was further validated in human HCCs. Bio-functional investigation revealed that LTBP1 inhibited cell proliferation in HCC cell lines, suggesting its potential role as a tumor suppressor in HCC. Gene expression microarrays revealed that signaling cascades (AKT (protein kinase B), STK33 (Serine/Threonine kinase 33) and MTOR (mechanistic target of rapamycin) pathways) were enriched in COX-2-induced HCC. In conclusion, this study demonstrated for the first time that enhanced COX-2 expression in hepatocytes is sufficient to induce HCC through inducing promoter hypermethylation by reducing TET1, silencing tumor-suppressive genes and activating key oncogenic pathways. Inhibition of COX-2 represents a mechanism-based target for HCC prevention.

Theoretical studies on the antioxidant activity of pinobanksin and its ester derivatives: Effects of the chain length and solvent

The effects of the ester group and solvent on the structure and antioxidant activity of pinobanksin were carried out using DFT calculation. First, the properties of the intramolecular hydrogen-bonds in the investigated compounds were studied. Second, the antioxidant capacities of the investigated compounds were analyzed by HAT, SET-PT and SPLET mechanisms from thermodynamic point. The conclusions are: (1) HAT mechanism is most favorable in the gas and CCl₄ phases, while SPLET mechanism is more favored in the CH₃CN and H₂O phases. In the CHCl₃ phase, the thermodynamically preferred mechanism is HAT for the 3-OH and 5-OH groups. While, HAT and SPLET mechanisms may run simultaneously for the 7-OH group. (2) Replacing the 3-OH group by ester group with different alkyl chains does not change much of the antioxidant activity of pinobanksin. (3) Besides, the 7-OH group contributes mainly to the antioxidant activities of the investigated compounds.

Detection of pyrazinamide resistance of Mycobacterium tuberculosis using nicotinamide as a surrogate

OBJECTIVES

Despite the importance of pyrazinamide (PZA) in tuberculosis treatment, PZA susceptibility testing is not routinely performed because of its acid pH requirement. We evaluated the Microplate Alamar Blue assay (MABA) to detect resistance to PZA using nicotinamide (NIC) as a surrogate in neutral pH and identify the appropriate cutoff point for the assay.

METHODS

The NIC minimal inhibition concentrations (MICs) for 125 Mycobacterium tuberculosis clinical isolates were tested by MABA at nine different concentrations (8-2000 μg/mL). The PZA susceptibility testing by the BACTEC MGIT 960 system was used as a reference method. The pncA gene and its promoter region were sequenced for all the recruited strains.

RESULTS

A total of 64 of 125 clinical isolates were identified as resistant by MGIT 960. Using a minimum inhibitory concentration (MIC) of >500 μg/mL as the cutoff concentration to define resistance presented the best fit of the MABA assay with the MGIT 960 outcomes. MABA demonstrated sensitivity of 100% (95% confidence interval, 92.6-100), specificity of 95.2% (95% confidence interval, 86.0-98.8) and an accuracy of 97.6% compared to the MGIT 960 method. Nine PZA susceptible strains defined by MGIT 960 also had pncA mutations; however, three of them were defined as PZA resistant by NIC MABA with MIC ≥2000 μg/mL.

CONCLUSIONS

The NIC substitution method for PZA susceptibility test is reliable, cheap, rapid and easy, which makes it promising for use in clinical laboratories.

A Novel Brucine Gel Transdermal Delivery System Designed for Anti-Inflammatory and Analgesic Activities

The seeds of Strychnos nux-vomica L., as a traditional Chinese medicine, have good anti-inflammatory and analgesic activities. However, it usually leads to gastrointestinal irritation and systemic toxicity via oral administration. In the study, it was discovered that a novel gel transdermal delivery system contained brucine, the main effective component extracted from Strychnos nux-vomica. Results showed that the brucine gel system inhibited arthritis symptoms and the proliferation of the synoviocytes in the rat adjuvant arthritis model, which indicated its curative effect for rheumatoid arthritis. Meanwhile, it significantly relieved the xylene-induced ear edema in the mouse ear swelling test, which manifested its anti-inflammatory property. Moreover, the brucine gel eased the pain of paw formalin injection in the formalin test, which demonstrated its analgesic effects. In addition, the brucine significantly inhibited lipopolysaccharide (LPS)-induced Prostaglandin E2 (PGE2) production without affecting the viability of cell in vitro anti-inflammatory test, which proved that its anti-inflammatory and analgesic actions were related to inhibition of prostaglandin synthesis. It is suggested that the brucine gel is a promising vehicle for transdermal delivery on the treatment of inflammatory disease.

Increased atmospheric ammonia over the world's major agricultural areas detected from space

This study provides evidence of substantial increases in atmospheric ammonia (NH₃) concentrations (14-year) over several of the worlds major agricultural regions, using recently available retrievals from the Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite. The main sources of atmospheric NH₃ are farming and animal husbandry involving reactive nitrogen ultimately derived from fertilizer use; rates of emission are also sensitive to climate change. Significant increasing trends are seen over the US (2.61% yr^-1), the European Union (EU) (1.83% yr^-1), and China (2.27% yr^-1). Over the EU, the trend results from decreased scavenging by acid aerosols. Over the US, the increase results from a combination of decreased chemical loss and increased soil temperatures. Over China, decreased chemical loss, increasing temperatures, and increased fertilizer use all play a role. Over South Asia, increased NH₃ emissions are masked by increased SO₂ and NO_x emissions, leading to increased aerosol loading and adverse health effects.

FAM83A is amplified and promotes cancer stem cell-like traits and chemoresistance in pancreatic cancer

Cancer stem cells (CSCs), also known as tumor-initiating cells (TICs), contribute to tumorigenesis, resistance to chemoradiotherapy and recurrence in human cancers, suggesting targeting CSCs may represent a potential therapeutic strategy. In the current study, we found family with sequence similarity 83, member A (FAM83A) is significantly overexpressed and associated with poorer overall survival and disease-free survival in pancreatic cancer. Overexpression of FAM83A markedly promoted, whereas inhibition of FAM83A decreased, CSC-like traits and chemoresistance both in vitro and in an in vivo mouse model of pancreatic cancer. Furthermore, overexpression of FAM83A activated the well-characterized CSC-associated pathways transforming growth factor-β (TGF-β) signaling and Wnt/β-catenin signaling. Importantly, the FAM83A locus was amplified in a number of human cancers and silencing FAM83A in associated cancer cell lines inhibited activation of the WNT/β-catenin and TGF-β signaling pathways and reduced tumorigenicity. Taken together, these results indicate that FAM83A has a vital oncogenic role to promote pancreatic cancer progression and may represent a potential clinical target.

Vasculoprotective Effects of Water Extracts of Black, Green and Dark Tea in Vitro

To investigate the preventive effects of tea on hyperglycemia and vascular complications of diabetes, we report the extraction and composition as well as the vasculoprotective effects of black tea extract (BTE), green tea extract (GTE), and dark tea extract (DTE). High Performance Liquid Chromatography (HPLC) and colorimetric methods were conducted to analyze for tea catechins, caffeine, polyphenols, amino acids and polysaccharides of BTE, GTE and DTE. The inhibitory effects of α-glucosidase, aldose reductase (AR), advanced glycation end-products (AGEs) and glucose uptake promotion effect in BTE, GTE and DTE were explored in vitro. Contents of six major catechin forms and total catechin as well as polyphenols are higher in GTE and DTE than BTE. BTE, GTE, and DTE showed the inhibitory effects of α-glucosidase, AR, and AGEs, but only DTE exhibited the glucose uptake promotion effect in HepG2 cells. The results suggest that regular consumption of tea can help prevent the progression of hyperglycemia and the vascular complications of diabetes.